1. Field of Invention
This invention relates generally to agricultural seed planters, and more particularly to a mechanism for delivering seed from the seed meter to the open seed trench.
2. Description of Related Art
Modern agricultural planters use seed metering devices designed to select and discharge individual seeds at regular intervals. It is desirable to precisely place the seeds in the seed trench to maximize a field's crop yield. Typically, the seed meters are mounted just below the seed hopper at heights ranging from about eighteen to about twenty-four inches above the ground surface. As a result, planters employing such metering devices also require seed tubes to direct the seeds into the open seed trench after the singulated seeds are discharged from the seed meter.
It has been found that the use of seed tubes to deliver the seeds to the seed trench have a negative effect on the uniformity of seed spacing in the trench. This is due to the fact that some of the seeds descend through the seed tube rapidly, substantially in a free-fall through the entire length of the seed tube, while other seeds contact the walls of the seed tube more frequently as they descend through the seed tube. The differences in velocities at which the seeds exit the seed tube toward the ground have an adverse effect on uniformity of seed spacing in the trench. Additionally, the momentum of the seed caused by the forward motion of the planter causes the seeds to tumble and bounce when introduced into the trench.
As a result, the deposited seeds are not uniformly spaced in the trench or they may bounce from the bottom of the trench. This may lead to the seed being placed shallower than desired. At times, the deposited seed can actually bounce completely out of the trench and lie on top of the ground. Seeds which lie on top of the ground will not germinate.
Thus, there is a need in the agricultural industry for an apparatus and method for controlled delivery of the seed between the seed meter and the open trench that improves seed placement accuracy within the open trench at the desired seed spacing thereby improving crop yield and the efficiency and profitability of farming operations.